1. Field of the Invention
The present invention relates to a three-dimensional antenna suitable for wireless transmission of digital data in local area networks.
2. Description of the Background Art
In wireless communications in local area networks (LAN) new stipulations are being added to conventional requirements (such as matched input impedance, good radiation characteristic, efficiency). Thus, for example, it is desirable for the antenna or a diversity antenna system to have space on a PCMCIA card. In laptop computers with communications capacity there are horizontal plug-in slots for these cards. An antenna system integrated on a PCMCIA card should therefore radiate roughly equally well in the horizontal plane in all directions. So that an antenna can be integrated on a card of this type, it must not exceed the height allowed by standards. Therefore, it is not possible in many frequency ranges to use a simple monopole antenna for these communications.